Fix CI failure in TIMESTAMP WITH LOCAL TIME ZONE test

Remove unnecessary function execution that triggered
ensure_tmp_tables_created, which is not needed to verify the
type remapping in metadata. Also make setup idempotent.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: yahonda

spec/plsql/procedure_spec.rb

@@ -2389,6 +2389,8 @@ def new_candidate(status)
 describe "Function with table type containing TIMESTAMP WITH LOCAL TIME ZONE" do
   before(:all) do
     plsql.connect! CONNECTION_PARAMS
+    plsql.execute "DROP PACKAGE test_timestamp_ltz_pkg" rescue nil
+    plsql.execute "DROP TABLE test_timestamp_ltz" rescue nil
     plsql.execute "CREATE TABLE test_timestamp_ltz (id NUMBER, ts TIMESTAMP WITH LOCAL TIME ZONE)"
     plsql.execute <<-SQL
       CREATE OR REPLACE PACKAGE test_timestamp_ltz_pkg IS
@@ -2413,7 +2415,6 @@ def new_candidate(status)
   end
 
   it "should remap TIMESTAMP(n) WITH LOCAL TIME ZONE to TIMESTAMP WITH LOCAL TIME ZONE" do
-    metadata = plsql.test_timestamp_ltz_pkg.test_fn.arguments
     return_metadata = PLSQL::Procedure.find(plsql, :test_fn, "TEST_TIMESTAMP_LTZ_PKG")
     fields = return_metadata.return[0][:element][:fields]
     expect(fields[:ts][:data_type]).to eq("TIMESTAMP WITH LOCAL TIME ZONE")